Ever since the development of a mechanized vehicle industry, the protection of such vehicles against theft has been of great concern, primarily due to their monetary value. In an early effort to protect such vehicles, manufacturers installed doorlocks so that the owner could lock the vehicle at times when the owner was not going to be present. Likewise, manufacturers fairly early began installing keyed locking switches that were interposed in the electrical ignition system of the vehicle. In such systems, an ignition key is necessary to actuate such a locking switch which then completes the electrical circuit in the electronic ignition system. While these systems proved useful, thieves have learned techniques for circumventing such systems.
Subsequently, manufacturers developed mechanical locking systems for theft prevention. One such example is an internal lock on the steering mechanism of the vehicle. Again, methods of circumvention were developed by those who wanted to steal the vehicles. Retro-fit locking appliances, such as Steering wheel lock bars were developed, but these proved cumbersome and inconvenient to use. Various electronic alarms have been employed to signal an alarm, such as by blowing the vehicle horn, blinking the vehicle's lights and/or sounding sirens, in an effort to reduce the likelihood of vehicle theft.
The aforementioned techniques, whether installed by manufacturers or employed as retro-fit systems, address the situation of theft of the vehicle usually while it is not in operation and unattended. For whatever reason, there has been a recent increase of vehicle theft just as the owner is starting the vehicle or while the vehicle is in operation but stopped in transit. Such latter situations often may occur at a traffic control signal or where the operator desires to momentarily step out of the vehicle such as for an errand. In this type of theft, recently referred to as "car jacking", a thief causes the operator to exit the vehicle either under force or under the threat of force, and the thief thereafter drives away with the vehicle, the operator's ignition keys necessary for maintaining access and operation of the vehicle and whatever possessions that are in the vehicle.
The present invention addresses the need for security systems to prevent or deter car jacking and employs a new and non-obvious integration of electronic proximity detection with electronic control circuitry of a vehicle. To this end, it should be understood in this description that the word "vehicle" could broadly encompass any motor powered transportation vehicle including, but not limited to, cars, trucks, boats, etc. Furthermore, the term "motor powered" in this context is not limited to vehicles powered by internal combustion engines but could include the developing technology of electric vehicles or other power systems as well. The present invention is directed to interact with the electronic control system of such motor powered vehicles whether it be the electronic ignition system of a typical internal combustion engine driven vehicle or any of the electronic circuitry of an electrically powered vehicle.
As noted above, the present invention integrates proximity detection with the electronic control circuitry of a vehicle. As is known, proximity detection may utilize a transmitter which transmits a signal, such as a radio signal, on a selected frequency, and a receiver tuned to receive that frequency. In some implementations of this technology, an alarm is sounded when the transmitter and receiver come within a threshold distance of one another, and the receiver thereby receives the transmitted signal, in order to sound an alarm indicating such closeness. Another implementation of such technology contemplates the indication of an alarm when the transmitter and receiver are separated a distance greater than a threshold communication distance.
An example of this technology is described in U.S. Pat. No. 4,260,982 issued Apr. 7, 1981 to DeBenedictis et al. In this patent, a pulse coded modulation responsive alarm system is provided to produce an alarm whenever the distance between a transmitter and a receiver exceeds a predetermined distance. This patent discusses that the system may be used to prevent loss of luggage or theft of other objects, and the patent discusses pre-existing alarm circuits used, for example, with automobiles. The earlier systems were proned to fail due to the possible presence of interference signals which the receiver would sense thereby falsely indicating that the transmitter was in the acceptable predetermined distance. To solve this, the transmitter in the '982 Patent broadcast a signal that is pulse coded at a selected frequency at a reduced duty cycle. The receiver, correspondingly, is tuned to the selected frequency and is adjustable in sensitivity to set the predetermined range of operation. A timer circuit is provided which reset each time a pulse is detected by the receiver but, after the absence of a series of pulses, the timer triggers and activates an alarm.
Other prior inventions have described alarm or electronic monitoring circuits which may be employed in a variety of ways. For example, U.S. Pat. No. 4,785,291 issued Nov. 15, 1988 to Hawthorne discloses a monitoring apparatus that is affixed to a person, such as a child, to be monitored and a receiver/monitor apparatus that may be maintained, for example, by a parent to monitor the movement of the child beyond a predetermined range. U.S. Pat. No. 4,675,656 issued Jun. 23, 1987 to Narcisse likewise shows an out-of-range personal monitor and alarm. U.S. Pat. No. 4,101,873 issued Jul. 18, 1978 to Anderson et al discloses a system to interrogate the position of objects to sound an audible response so that the object can be located. U.S. Pat. No. 4,598,272 issued Jul. 1, 1986 to Cox likewise shows an electronic monitoring system for monitoring a persons whereabouts. U.S. Pat. No. 4,792,796 issued Dec. 20, 1988 to XXX also shows an encoded transmission signal and circuitry that generates an alarm for indicating failure of reception of the coded signal to monitor the presence or absence thereof.
Despite the development of both the security devices described above, there remains a need for improved security systems which protect owners and operators from theft of their vehicles. There is further a specific need for systems which protect against or serve to deter car jacking and similar crimes. There is a need for such system which can be manufactured as original equipment on a vehicle or easily integrated with an existing vehicle.